Sutures for closing incisions in human skin are well known. The sutures are applied by physicians using a needle to pull the suture material through the two sides of the incision. The suture material is tied which fastens or apposes the two sides to allow healing. The suture material may be non-absorbable such as silk, polyester, etc. or it may be formed from bioabsorbable materials such as polyglycolic acid polymers. Applying sutures in this way requires skill and dexterity. Also it exposes the operator to possible needle stick injury. For these reasons and because of the time that it takes to apply sutures, other fasteners have been developed, the most popular of these being referred to as staples.
Surgical staples are made of non-reactive metals and are strong enough to hold the tissues together once the ends of the staple have been bent inward. Although staples are faster and safer to apply than sutures, they have disadvantages. Because they penetrate the epidermis and remain exposed on the surface of the skin, they (i) present an opportunity for infection, (ii) the wound must be kept dry until the staples are removed (5-7 days), and (iii) the patient must return for removal which requires another device, is time consuming, inconvenient and can cause discomfort.
Recently staples have been made of bioabsorbable plastics so that they can be applied below the skin and will not require removal. To have sufficient strength to penetrate the skin and secure the tissue, the plastic typically must be much larger in cross section than an equivalent metal staple. For example, a staple wire with diameter of 0.65 mm in metal would need to have a diameter of 2.5 mm to have the same bending or buckling strength if made of plastic. Hence, the bioabsorbable staples tend to be bulky and to occupy significant volume within the wound. In addition, the means of applying the plastic staple may be complex.
U.S. Pat. No. 6,726,705 relates to a mechanical method and apparatus for fastening tissue.